Gunicorn version 21.2.0 does not properly validate the value of the 'Transfer-Encoding' header as specified in the RFC standards, which leads to the default fallback method of 'Content-Length,' making it vulnerable to TE.CL request smuggling. This vulnerability can lead to cache poisoning, data exposure, session manipulation, SSRF, XSS, DoS, data integrity compromise, security bypass, information leakage, and business logic abuse.
CVSS Details
- CVSS 3.0 Base Score: 7.5
- CVSS 3.0 Vector: (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N)
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Debian | — | Upgrade gunicorn | May 15, 2025 | Mar 20, 2025 |
| Dell Powerstore Dsa2025342 | — | Upgrade Dell PowerStoreOS to the latest version | Jan 13, 2026 | Sep 2, 2025 |
| Suse | — | Upgrade python311-gunicornUpgrade python3-gunicorn | Dec 5, 2025 | Mar 25, 2025 |
Prioritise with Active Threat Intelligence
With curated Threat Intelligence, you can see which vulnerabilities truly put you at risk, prioritize what matters most, and act before attackers do.
Explore Intelligence Hub